Electrical connector having unbonded insulation thereon



I Nov. 10., c. D. KINDELL ETAL 3,539,707 I ELECTRICAL CONNECTOR HAVINGUNBONDED INSULATION THEREON Filed Nov. 4, 1968 VULCA/V/ZED PAPERVULCA/V/ZED I PAPER IN VEN TOR Cou- DAVID Kmoeu. Tenwemce Qoaem' PmwolzUnited States Patent U.S. Cl. 17484 Claims ABSTRACT OF THE DISCLOSURE Anelectrical connector has a generally U-shaped configuration withinsulation covering an exterior surface in an unbonded manner, theinsulation being held in place on the connector via gripping meansprovided by the connector.

This invention relates ,to electrical connectors and more particularlyto electrical connectors having insulation held in place thereon viagripping means provided by the connectors.

It is known to provide an essentially U-section metal ferrule forcrimping to a wire, with a film of insulating material, for examplepolyethylene terephthalate which is bonded to the outer surface of theferrule. A disadvantage of this'unknown electrical connector is that thebonding of the film to the ferrule is unduly time-consuming.

According to the invention, an electrical connector comprises anessentially U-section metal-crimping ferrule, the outer surfaceof whichis covered with a film of insulating material which extends into theferrule and is gripped within the ferrule between portions of theferrule to retain the film in position on the ferrule. The portions ofthe ferrule may be bent out therefrom and co-operate with one another togrip the free longitudinal marginal portions of the film, being formedfor example by lugs or lugs co-operating with ribs. In the interests ofeconomy the film may be made of vulcanized paper.

The ferrule may have internal slots into which insulated electricalwires are forced by side wall portions of the ferrule to produceelectrically conductive contact between the electrically conductive coreof the wires and the walls of the slots, the side wall portionsco-operating with further internal portions of the ferrule to grip thelongitudinal marginal parts of the film.

An object of the invention is to provide an electrical connector onwhich insulating means is disposed and held in position thereon bygripping means provided by the connector.

Another object is the provision of gripping means of an electricalconnector which grips ends of insulation means to hold the insulationmeans in position along an exterior surface of the connector.

A further object is to provide gripping means of an electrical connectorwhich hold insulation means in position on the connector as well asdefining stufiing means for stufiing electrical conductors to beterminated in the connector within conductor-engaging area means of theconnector.

For a better understanding of the invention, reference will now be madeby way of example to the accompanying drawing, in which:

FIG. 1 is a perspective view of an essentially U-section metal crimpingferrule;

FIG. 2 is an enlarged end view of an electrical connector according tothe invention and comprising the 3,539,707 Patented Nov. 10, 1970ferrule shown in FIGURE 1, two insulated electrical wires in the ferrulebeing shown in section;

FIG. 3 is a cross-sectional view through the connector when crimped tothe wires; and

FIGURE 4 is a cross-sectional View illustrating a modification of theconnector.

Reference will now be made to FIGURES 1 and 2. An essentially U-sectionmetal-crimping ferrule 4, for example of brass comprises a base 8 havingstruck therefrom two upstanding tongues 10. Each tongue 10 has a pair ofspaced notches 12 opening into its upper (as seen in FIGURES l and 2)edge which has inclined portions 16 and 20 forming wire-guiding mouths.The side walls of the ferrule 4 have bent-in ribs 22 and struckouttongues 24, the free ends 2 6 of which overlap the ribs 22.

As shown in FIGURE 2, the outer surface of the ferrule 4 is covered byan insulating film 27 which may, in the interests of economy, he ofvulcanized paper. The film 27 has portions 28 which overlap the freelongitudinal ends 30 of the ferrule 4 and extend within the ferrule andbetween the tongues 24 and ribs 22. The tongues 24 have been benttowards the ribs 22 to grip the free longitudinal marginal parts 32 ofthe film 27 between the tongues 24 and ribs 22. The film 27 is thusretained tightly wrapped about the ferrule 4.

In use, two insulated electrical wires 34 having insulation 36 andelectrically conductive metal cores 38 are placed in the ferrule 4 so asto lie on the edge portions 16 and 20 of the tongues 10. A pair ofconnector-crimping dies (not shown) are closed about the connector tocompress it to the shape illustrated in FIGURE 3, in which the sidewalls of the ferrule 4 have been curled over so that each rib 22 andalong with ends 30 along one side of ferrule 4 drives one of the wires34 into one of .the notches 12 so that the electrically conductive 7core 36 of the wires 34 makes electrical contract with the walls of thenotches 12.

As shown in FIG. 3, the marginal parts 32 of the film 27, which remaingripped between the tongues 24 and ribs 22, are carried down along thenotches 12 and continue to hold the film 27 firmly about the ferrule 4,portions 40 of the film engaging one another centrally of the ferrule 4and'throughout its length.

According to a modification of the connector just described, the ribs 22are replaced by inwardly bent lugs 42 (FIGURE 4), the tongues 24 beingbent as indicated by broken lines in FIGURE 4 to grip the marginalparts32 of the film 27.

A further advantage of the use of vulcanized paper as the film is thatthis material has little or no plastic memory so that the film tends toremain in position about the side walls of the ferrule.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

The invention is claimed in accordance with the followmg:

1. An electrical connection comprising a U-shaped metal crimping ferrulecrimped about a wire electrically to connect the ferrule to the wire, aninsulating film surrounding the ferrule, first and second longitudinalmarginal portions of the film extending within the ferrule, a first pairof projections extending from a first wall of the ferrule and grippingthe first longitudinal marginal portion between smooth surfaces of theprojections of the first pair, a second pair of projections extendingfrom a further wall of the ferrule and gripping the second marginalportion between smooth surfaces of the second projections, the first andsecond marginal portions lying in spaced substantially coplanarrelationship within the terrule.

2. A connector according to claim 1, in which the walls of the ferruleare joined by a base member presenting slots containing insulated wires,the wires being held in position in the slots by one projection of eachpair, the other projection of each pair pressing on the one projectionof each pair via the longitudinal marginal portion which is grippedbetween the projections of that pair.

3. A connector according to claim 1, in which the insulating film ismade of a paper material.

4. An electrical connector comprising a generally U- shaped memberhaving leg members connected together by a base member, a dielectricmember extending along an exterior surface of said U-shaped member andhaving sections extending along inner surfaces of said leg members, andgripping means provided by said leg members inwardly from outer edgesthereof gripping said sections thereby securing said dielectric memberin position of said U-shaped member and providing an insulatedconnector, said gripping means defining tongue portions struck out fromsaid leg members and being directed toward free ends of said legmembers, said leg members adjacent said free ends and extending alongsaid tongue portions providing ribs directed inwardly toward said tongueportions.

5. An electrical connector according to claim 4 wherein said base memberincludes upstanding tongue members having conductor-receiving Slots,said leg members from upper ends of said tongue members to said freeends thereof defining stufiing means for stuffing insulated electricalconductors in said conductor-receiving slots with said slots strippingthrough insulation on the conductor and electrically engaging conductormeans thereof.

6. An electrical connector according to claim 4 wherein said sectionsextend along the entire lengths of said leg members.

7. An electrical connector comprising a generally U- shaped memberhaving leg members connected together by a base member, a dielectricmember extending along an exterior surface of said U-shaped member andhaving sections extending along inner surfaces of said leg members, andgripping means provided by said leg members inwardly from outer edgesthereof gripping said sections thereby securing said dielectric memberin position on said U-shaped member and providing an insulatedconnector, said gripping means defining tongue portions struck out fromsaid leg members and being directed toward free ends of said legmembers, and lugs struck out from said leg members and being directedinwardly toward said tongue portions.

8. An electrical connector comprising a generally U- section crimpingferrule having a pair of side walls connected together by a base member,a film of insulating material covering an outer surface of the ferruleand having portions extending along inner surfaces of the side walls,and projection means extending from each side wall and spaced inwardlyfrom ends thereof, said projection means extending in a generaldirection toward the ends of the side walls and gripping said portionsof said film between said projection means and said inner surfaces ofsaid side walls.

9. A connector according to claim 8, in which the projection meanscomprise lugs struck out from the side walls and ribs bent out from theside walls.

10. A connector according to claim 8, in which the film is made of apaper material.

References Cited UNITED STATES PATENTS 1,936,869 11/1933 Deaver 174-ssXR 3,303,266 2/1967 Thompson 339-96-XR 3,320,354 5/1967 Marley et al.174-88 XR DARRELL L. CLAY, Primary Examiner US. (:1. X.R.

